Separating liquids from solids and apparatus therefor



Nov. 23, 1937. N. R ANDREWS 2,100,118

SEPARATING LIQUIDS FROM SOLIDS AND APPARATUS THEREFOR 'Filed Feb. 27, 1936 jVqi'lzan z'gl fflrzdrems,

W ww w w m a a 3 Q Patented Nov. 23, 1937 UNITED STATES PATENT OFFICE SEPARATING LIQUIDS FROM SOLIDS AND APPARATUS THEREFOR,

6 Claims.

' This invention relates to separating liquids from solids and apparatus therefor; and it comprises a method of separating liquids from solids wherein a plurality of interconnected, radially-spaced annular separating zones are establishedand maintained in rotary motion, material to be separated is continually fed into the central separating zone and solids and liquids are collected separately at the periphery; and it also comprises a centrifugal 10 machine for continuously separating solids from liquids, said machine comprising a rotatable shaft, two spaced parallel plates mounted thereon for rotation, two spaced annular sheets corrugated in circles mounted between said plates and so disposed as to provide a sinuous passagetherebetween for material to be separated, certain sections'of said corrugated sheets being foraminous in order to provide outlets for liquids from said sinuous passage, other foraminous sections being provided for the introduction of wash liquors and other fluids into said sinuous passage, means for feeding material to be separated centrally between said corrugated sheets, and means for collecting sepa-. rated liquids and solids; all as more fully hereinafter set forth and as claimed.

Many types of centrifugal separators have been proposed for use in the sugar industry, for example, where such machines are used for separating crystallized sugar from massecuite, a

magma of sugar and syrup. The conventional separators in use in this industry comprise a rotating basket surrounded by a casing which collects the separated syrup. The basket is charged with massecuite and rotated for sepation of the syrup and finally the sugar is discharged. This batch method of separation has many disadvantages since a large proportion of the total energy consumed in the operation is required for starting the machines.

mittent operation greatly limits the output per machine. The sugar is not uniformly processed as the inside layers within the basket retained an unequal proportion of syrup or wash vwater. The product is never uniform owing to the fact that all the wash water passes through the thick wall of the sugar in the basket. Some of the grains in the inner layersdissolve which results in uneven grain size.

While a few types of centrifugal machines have I rial.

The inter-'- guide plates are placed-these guide plates largely serving to dissipate the kinetic energy of the material which is acquired in each proceeding separating basket. In each basket it is therefore necessary to accelerate the material from sub- 1"; stantially zero velocity. A common .fault with these machine is that the material in passing. therethrough contacts surfaces moving with a relatively slower velocity.

I have developed an extremely simple centrif- 10 ugal separator which is capable of separating solids and liquids continuously at a high operating rate and having a design which is so simple and fool proof that it can be constructed cheaply and operated by inexperienced labor. The new 15 design eliminates the mentioned faults of the continuous type of separators.-

In my'separator all solid grains or particles entering the basket are alternately moved upwardly and downwardly over successively inclined separating surfaces forming a plurality of passes and finally discharged at the periphery of the basket. The liquid separated out upon each of said passes can be removed separately or in bulk from the machine. At no point in its transit through the basket is gravitational force solely depended upon for movement of the mate- The material in its transit comes in contact only with parts and surfaces which have a greater linear velocity than any passed over previously. During its passage through the basket the material may be washed and treated with air for drying or with bleaching agents.

' In the accompanying drawing I have shown, more or less diagrammatically, a preferred form of apparatus which falls within the purview ;of my invention. In this showing:

Fig. l is a vertical section through the center of my centrifugal separator;

Fig. 2 is a partial fragmentary vertical sec- 40 tion of a modification; and v Fig. 3 is a horizontal detail section taken along the line 33 of Fig. 1.

In the figures like parts are indicated by like, reference numerals. by a source of power not shown, supports and operates the centrifugal basket shown generally at 2. The basket is formed of two annular plates 3 and 4 which are bolted-together and held in spaced relationship by means of bolts 5. Shaft I is secured to lower plate 4 by suitable means. such as bolts '6. Between the plates 3 and 4 two corrugated annular sheets I and 8 are-mounted, these sheets being. advantageously soldered orwelded to the upper and lower plates, respective-v A rotatable shaft I, driven 45/,

1V, at each corrugation, and being so disposed as to leave a continuous passage for solids and liquids between them. The sheets are provided 3 serve to conduct away the liquid which is separated from the solids. This liquid passes through ports I5, I6, I'I, I8,-and 69 which are provided in the top plate. Ports I5 and I6 communicate with the passageway between guide plates II and I2, while ports I1, I8, and communicate with the passageway between guide plate II and top plate 3.

The lower plate 4 of the basket is also provided with guide plates I9 and 20, these plates being mounted on annular ribs 2] and 22, respectively, and being held in spaced parallel position by means of spacer washers 23 and 24 mounted on bolts 5. The lower plate 4 is provided with port 56, serving to pass separated liquid from the interior of the basket to the passageway formed between guide plates I9 and 29. Ports 51, 58, and. 59 likewise serve to pass liquid to the passageway between guide plate I9 and the bottom plate 4 of the basket.

The centrifugal basket is surrounded at. its periphery by a stationary annular sectionalized gutter casing 25 which serves to receive the materials discharged from the machine. Thus, section 26 receives the liquid discharged between guide plates II and I2 and section 21 that discharged between guide plate I I and the top plate 3. Section 28 receives the solids discharged from the machine between corrugated sheets I and 8, while sections 29 and 39 receive the liquids discharged between the bottom plate 4 and guide plate I9, and between guide plates I9 and 29, respectively. The materials discharged may be conveyed to separate places of disposal. The liquids, for example are usuallydrawn ofi from the gutters by means of pipes 3|, 82, 83, and 84. The solids are usually collected in an enlarged gutter section, such as that shown at 28 which tapers down to a funnel discharge 32. This funnel may discharge upon an endless belt, not shown, if desired. The lower gutter sections 29 and 39 may be secured to'the outer casing 25 by means of braces 80.

In the embodiment shown in the drawing provision is made for washing the solids during their passage through the centrifugal basket, also .for the introduction of air for drying or of a bleaching agent, for example. This is accomplished by means of guide sheets 33 and 34 which terminate centrally in upstanding flanges 35 and 36 respectively these flanges forming an annular trough 31. A pipe 38 communicates with this trough and may supply wash water to this trough and therefore to the space between guide sheets 33 and 34. A second annular trough 39 is formed between flange 35 and the upstanding flange 49 forming part of top plate 3. A pipe 4I communicates with this trough and may be used to supply heated air or bleaching agent, for ex- 75 ample, to the trough and therefore to the space between guide sheets I2 and 33. Wash water introduced through pipe 38 is thrown by centrifugal force into the space between guide sheets 33 and 34 and passes into the basket through tubes 42 into the space which is formed between deflector sheet 43 and foraminous section 44 of corrugated sheet I. The wash water, of course, then passes through the perforations of section 44 and enters the space between the two corrugated sheets I and 8, serving to wash the solids which pass between these sheets.

If heated air or steam is passed through pipe 4I it is sucked into the space between guide sheets I2 and 33 by means of the fan action of perforations of section 48 and into the space between corrugated sheets I and 8, where it serves to dry the solids passing through this space. If desired a bleaching gas or liquid may be passed through pipe 4I instead of heated air or steam.

The centrifugal basket is charged by means of a pipe 49. The material to be separated first strikes a deflecting disc 85. Owing to the centrifugal force the material is thrown outwardly against the interior of the flange 40, where it is temporarily held by centrifugal force, and then passes downwardly across the perforated face 52 of corrugated sheet I. Part of the liquid in the materialpasses through the perforations in face 52 and finds its way through port I5 and eventually into gutter casing 26 and pipe 34.

is removed, this liquid passing through the perforations in face 5I and finding its way through port 56 and eventually into gutter section 39 and. pipe 3|. At the top of the face 5I, the material is thrown by the centrifugal force against a perforated face 53, where it loses additional liquid, and so on through the machine. As the flow of material continues along the sinuous path formed between corrugated sheets I and 8, it loses liquor at each perforated face, gradually becoming thicker- The liquor which is separated on the perforated face 53 is deflected into the port I6 by means of the deflecting sheet 43. The concentrated material then meets wash water which is introduced through pipe 38 as described previously, this wash water passing through the perforated face 44 of the corrugated sheet I. The

added wash water and the remaining liquor arev separated on the following perforated faces, passing through the ports 51, 58, and 59 of the lower plate 4 and through the ports I'I, I8, and 60 of the top plate 3 and eventually reaching the gutter casing. The liquor passing through the perforated section SI of corrugated sheet I is deflected through port I8 by means of the deflector sheet 41. The material passing through the followingpass then meets heated air or bleaching gas, which is passed through pipe 4| as described previously. The solid material which is finally discharged into section 28 of gutter casing 25 may be substantially dry and bleached.

In order toprevent air from being sucked through the machine a labyrinth seal such as replaced by a packing gland, not shown, if desired In Fig. 2 a modification is illustrated in which a top suspension is provided, the basket being suspended from shaft I and fastened thereto by means of bolts 6. In this modification, it will further be noted that the perforated faces over which the material to be separated passes down- 'wardly are more nearly vertical than those faces mal speed is many times that of gravity, hence the difference in rate of flow due to the action of gravity is small.

While I have described what I consider to be the best embodiments of my separator, it is evident that many modifications can be made without departing from the purview of the present invention. It is evident, for example, that as many passes or corrugations as desired may be employed in my separator. The corrugated sheets I and 8 can be made in one piece or they can be made in sections, the surface of each section corresponding to the surface of the frustrum of a cone. The several sections can then i be .welded or soldered to the top and bottom various angles to the vertical.

plates and to each other. The corrugated sheets can be either slotted or perforated in order to provide for separation of liquids. The -separating surfaces may be covered with filtering material if desired. Various ways of introducing on a single shaft. The liquid recovered from each pass may be collected separately by providing suitable guide sheets above and below the basket. The several perforated sections of the corrugated sheets may be sloped or pitched at The pitch may increase or decrease progressively from the center outwardly. I I usually prefer to have the sections near the center more nearly vertical, as shown in Fig. 1,1but this can be reversed for special purposes. Itis merely necessary that the pitch of the screening surfaces be such that, at any point of said surfaces, the combination of forces acting'on the material to be separated results in the movement of the material in the general direction of the periphery of the basket. The design can be altered to suit the material which is to be separated. The range of materials which can be processed in my separator is very wide, covering substantially all types of solid and fluid mixtures. Other modifications which fall within the scope of the followingclaims will be immediately evident to those skilled inthe art.

What I claim is:

'1. A centrifugal machine comprising a rotatable shaft, two spaced parallel plates mounted on said shaft, two spacedannular sheets corrugated in circles mounted between said plates and so disposed as to provide a sinuous radial passage therebetween for material to be separated, peripherally disposed faces of the corrugations of said corrugated sheets being foraminous in order to provide outlets for liquids from said sinuous passage,

means for feeding material centrally into said sinuous passage and means for collecting separated liquids and solids.

2. A centrifugal separator, comprising a rotatable shaft, two" spaced parallel plates mounted for rotation with said shaft, an annular sheet corrugated in circles and secured to each of said plates, said sheets being so constructed and arranged as to define therebetween a sinuous radial passage for material to be separated, the peripherally disposed faces ofeach corrugation of said sheets being foraminous for the passage therethrough of liquid to be separated from solid material in said sinuous passage, outlets associated with each of said plates for liquid passing through the foraminous portions of said sheets to spaces above and below said sinuous passage respectively,

' means for collecting the separated liquid both above and below said sinuous passage, and other means for collecting the solids separated from the liquids and passing through said sinuous passage to the periphery of said sheets.

3. A centrifugal separator, comprising a substantially vertical rotatable shaft, spaced supporting means associated with and arranged for rotation by said shaft, a spaced annular sheet corrugated in circles mounted on each said sup porting means, said sheets being so constructed and arranged as to provide therebetween a sinuous radial passage for material to be separated and having the peripherally disposed face'of each corrugation thereof foraminous to provide outlets for liquid separated from the solid material passing through said passage, means for supplying wash water to the above defined rotating elements of the separator adjacent to the axis of rotation thereof,,means rotatable with said shaft for conducting wash water radially, outward from the point at which it is supplied toward portions of said sinuous passage radially more distant from the axis of said shaft than the point of supply of the wash water, and means for conducting wash water from the last named means into said sinuous passage to wash the solid materials passing therethrough at intermediate portions of said sinuous passage, whereby the centrifugal force acting upon the wash water during its passage through said conducting means serves to force it at relatively high velocity onto the solids to be washed thereby.

4.. A centrifugal separator, comprisiriga substantially vertical rotatable shaft, spaced supporting means associated with and arranged for rotation by said shaft, a spaced annular sheet corrugated in circles mounted on each of said supporting means, said sheets being so constructed and arranged as to provide therebetween a sinuous radial passage for material to be separated and having the peripherally disposed face of each corrugation thereof foraminous to provide outlets for liquidseparated from the solid material passing through said passage, .means for supplying steam to the above recited tation to portions of said sinuous passage adjacent to the periphery thereof, and a plurality of vanes rotatable with said shaft for forcing the steam through said conducting means to cause it to impinge at a relatively high velocity upon the solid materials to be dried thereby.

5. A centrifugal machine comprising a substantially vertical rotatable shaft, two spaced-parallel, 15

circular plates mounted substantially horizontally on said shaft to rotate therewith, each of said 1 means for collecting solids discharged from the periphery of said sinuous passageway.

6. The centrifugal machine of claim 1 wherein said rotatable shaft is substantially vertical and said parallel corrugated platesare generally horizontal, and wherein the portions of said corrugated sheets, over which the material to be tical than the adjacent portions, over which said material flows upwardly, whereby the effect of gravity'upon the peripheral flow of the material to be separated is at least partially compensated.

NATHANIEL R. ANDREWS.

I separated flows downwardly, are more nearly ver- 

